This counter tallies error-free unicast packets received across all ports in a group, i.e. normal point-to-point traffic destined for specific hosts rather than broadcasts or multicasts. It is the bulk of typical client-server traffic an admin would expect to see dominate a healthy group's packet mix. A sudden drop in gspPhysicalOk on group 3 while gspBroadcastOk stays flat could indicate a host on that group has lost its unicast connectivity.